I would suggest that vision and balance are indeed related to one another= but for somewhat different reasons. The inability to produce the necessa= ry stride length required by the environment for walking at any given time i= s = in my opinion a perceptive (i.e. vision) or processing (i.e. vision processing) problem in PD'ers. (The ways to overcome this is predominant= ly vision mediated). Normal walking generally involves the forward displacement of one's center of gravity past the fall point with a subsequent stride of adequate length to catch oneself prior to falling. = Short stride or shuffling gait is compensatory for this perceived lack of= available stride length. It's a way of walking that keeps one's center o= f gravity under foot rather than forward displaced. Balance problems occur= when the environment suprises us with a sudden need to decelerate, stop= and maneuver. Our velocity exceeds the ability of the short stride to safely slow us down and so we appear out of balance and fall. regards, Tom Riess =